Regenerated artificial structure and process of making same



Patented Nov. 19, 1935 UNITED STATES REGENERATED ARTIFICIAL STRUCTUREAND PROCESS OF MAKING SAME Leon Llllenfcld, Vienna, Austria No Drawing.Application March 13, 1930, Serial No. 435,648. In Austria March 16,1929 46 Claims.

The present invention relates to the production of artificial structures(including artificial threads, films, and coated products, etc.) fromhydroxy-alkyl derivatives (ethers) of cellulose, which products willhave satisfactory dry and wet tenacity, at least a fair extensibilityand-a good appearance, all as will be hereinafter set forth andillustrated in certain examples and as claimed.

In carrying out the process of the present invention solutions ofhydroxy-alkyl cellulosexanthates can be easily converted into artificialstructures by-giving their solutions the shape of the desired artificialstructure, for example thread, and acting upon the shaped solution witha coagulating agent. This agent may or may not also have a plasticizingaction, or if desired the shape solution can be acted upon first with acoagulating agent and thereafter the freshly coagulated artificialstructure can be acted upon with a plasticizing agent. The-plasticizingtreatment is in some cases usefuLbut the invention in its broader aspectis not restricted to this step.

The alkaline solutions of xanthates of such hydroxy-alkylcelluloseethers as are prepared by reacting upon cellulose, in the presence, ofan alkali, with hydroxy-alkylating agents (e. g. halogenhydrins) can beconverted into artificial structures (e. g. threads) by treating thesaid xanthate solutions, while having the shape of the desiredartificial structures, with an acid solution, e. g. the said xanthatesolutions can be spun, through a spinnerette, into a setting bath knownin the viscose industry, whether or not said bath also has aplasticizing action on the freshly coagulated artificial thread.Accordingly the plasticizing baths referred'to in the precedingparagraph, while often advantageous, are

not necessary in the. process.

The artificial structures produced according to the present inventionhave a satisfactory and, in some instances, even excellent tenacity inthe dry and wet state and a pliability, extensibility and elasticitysufllcient for all practical purposes.

This .result of the present invention is rather surprising, consideringthat it is to be assumed, that, on contacting a shaped solution of ahydroxy-alkyl cellulose xanthate, for example a thread-like stream (ascoming through the openings in a spinnerette) with a precipitatingagent, for example an acid, the hydroxy-alkyl derivative of cellulose towhich, in its xanthate, the CSS-group has been attached, is regenerated.

In other words: Although the artificial materials of thepresentinvention probably consist of, or

contain, the very same hydroxy-alkyl ethers of cellulose which are thebasic constituents of the artificial materials made heretofore fromhydroxy-alkyl ethers of cellulose, with -regard to their properties, theshaped artificial structures 5 made by the present process are superiorto any 5 artificial structures heretofore produced from hydroxy-alkylcellulose ethers.

The present invention consists in making artificial threads or otherproducts by bringing into 10 the appropriate form or shape a solution ofa cellulose compound which contains at least one CSS-group and at leastone radical of a dior poly-hydroxylic alcohol and which cellulosecompound is produced by converting the whole or 15; a part ofth'cellulo'se employed into a hydroxy- I alkyl ether of cellulose andthereafter treating the product thus obtained in the presence of analkali with carbon bisulphide, and then acting uponv this shapedsolution with a coagulating 20, agent which may also have a plasticizingeffeet on the material during, or immediately after, its coagulation, oracting upon the shaped solution first with a coagulating agent andthereafter if desired, acting with an agent which has 5; a plasticizingeifect on the freshly coagulated material. The hydroxy-alkyl derivativesof cellulose which are intended to be converted into their xanthates maybe produced according to the processes described in my concurrentlyfiled ap- 0 plication Ser. No. 435,647 (now U. S. Patent 1,858,097) ormy U. S. Patent 1,722,927.

Stated otherwise, the invention of the present case comprises bringing asolution of a xanthate of a hydroxy-alkyl derivative of cellulose or of5 a near conversion product of cellulose (made for instance by theprocess set forth in my U. S. Patent 1,858,097, e. g. by xanthating thehydroxyalkyl derivatives of cellulose, which hydroxyalkyl derivativesare at least partially soluble in 40 caustic alkali solution and whichmay be produced by the process set forth in my Patent 1,722,927, i. e.by a process in which cellulose or a near conversion product is treatedwith a hydroxyalkylating agent in the presence of an alkali) into theshape of the desired artificial structure and contacting the same with acoagulating agent. The coagulating agent may be any solution known as asetting bath for viscose, (such for example as dilute mineral acids,strong mineral acids, acid salts, mixtures of acid solutions with salts,etc.) The hydroxy-alkyl derivatives of cellulose, before the 'xanthatingstep may be soluble or insoluble in alkaline solutions (e. g. in causticalkali solutions), but the xanthated products will be soluble in suchalkaline solutions.

The hydroxy-alkyl cellulose xanthates may be worked up into artificialstructures, for instance threads, alone or in conjunction with othercolloids, such as cellulose xanthate, by mixing a solution of ahydroxy-alkyl cellulose xanthate with viscose orby dissolving cellulosexanthate (sulphidized alkali cellulose) in a solution of a hydroxy-alkylcellulose xanthate or by dissolving a hydroxy-alkyl cellulose xanthatein viscose, or by conducting the present process so that the carbonbisulphide is allowed to act in presence of caustic alkali upon amixture of cellulose and a hydroxyalkyl derivative of cellulose, forexample by treating alkali cellulose with a halohydrine under suchconditions that only part of the alkali cellulose is converted into ahydroxy-alkyl ether of cellulose and thereafter by the action of carbonbisulphide converting the reaction mass into a mixture of ahydroxy-alkyl cellulose xanthate with cellulose xanthate. Also otheralkali-soluble derivatives of cellulose or alkali-soluble cellulosehydrates, 01'. proteins, or gelatine, or the like, may be used asadmixtures to the hydroxy-alkyl cellulose xanthates or their solutions.

Any suitable softening agents, such as glycerine or a glycol or a sugar,such as glucose, or a soap or Turkey-red oil, or a drying or non-dryingoil, or any known elasticizing agents, for example a halogen derivativeof a dior poly-hydroxylic alcohol, particularly a halohydrine, such as adichlorohydrine or a monochlorohydrine for example ethylenechlorohydrine may be added to the solutions of the hydroxy-alkylcellulose xanthates, or of their mixtures with cellulose xanthate.

As stated above, according to the present invention, the artificialstructures, for example threads, are produced by giving a solution orpaste of a hydroxy-alkyl cellulose xanthate the appropriate shape orform, and acting upon the shaped solution with a coagulating agent whichmay also have a plasticlzing effect on the material during, orimmediately after, its coagulation, or acting upon the shaped solutionfirst with a coagulating agent and thereafter, if desired, with an agentwhich has a plasticlzing effect on the freshly coagulated material.

Particularly useful plasticlzing agents, which in the formermodification of the present process act also as coagulating agents, areliquids which have a high content of strong mineral acid, particularlysuch baths as contain not less than per cent. of sulphuric acidmonohydrate or an equivalent quantity of another mineral acid. But alsoother plasticizing .agents can be employed, for example baths containinga fair amount of a zinc halide alone or mixed with an acid.

But within the broad scope of the invention, any chemical coagulatingorprecipitating agent or mixture of precipitating agents or mixture ofprecipitating agents with other inorganic or organic substances, knownas setting baths in the viscose art may be usedini, the present process.Excellent results, particularly with regard to tensile strength, areobtained when the freshly coagulated material is exposed to the actionof 'a plasticizing agent (but this step is optional).

This purpose can be accomplished either by using as the setting bath aliquid which has a coagulating effect on the shaped solutions of thehydroxy-alkyl cellulose xanthates and a plasticizing effect on thecoagulated solution (for acid), or by employing as the setting bath a.liquid that has only a coagulating effect on the formed solutions ofhydroxy-alkyl cellulose xanthates (for example, any coagulating but notplasticlzing bath known in the viscose art) and subsequently, (ifdesired) acting upon the freshly 10 the shaped hydroxy-alkyl cellulosexanthate sol ution.

The methods for the bringing of the solutions of the hydroxy-alkylcellulose xanthates into the form of artificial structures, for examplethreads,

for coagulating, washing and finishing, desulphurizing, bleaching, etc.,are similar to the methods of forming artificial structures, e. g;threads, in the viscose art in general and the artificial silk art inparticular, and the special methods of producing artificial structures,for 30.

example threads by means of coagulating agents that have also aplasticlzing effect on the freshly coagulated artificial structures havebecome known in the art under the name of Lilienfeldsilk produced by theso-called Lilienfeld processes 35 (see my U. 8. Patents 1,683,199 and1,683,200) and therefore it seems superfluous here to enter into fullparticulars of these procedures.

If desired, the extensibility of the artificialstructures, particularlythreads, produced ac- 4a.-

cording to the present process may be still more increased by treatingthem with suitable shrinking agents, i. e. such shrinking agents as haveno dissolving effect on the thread, for example with some of theshrinking agents mentioned in my U. S. patent applications, Ser. No.308,589;

186,575; 367,154 and 367,150, now Patents 1,989,098 to 1,989,101inclusive, and 2,001,621.

Thus the threads can be subjected to the'action of any mercerizing agent(e. g. NaOH solution preferably of 15-18% strength, or stronger, or NaaSsolution of 15% or stronger) preferably applied hot, while not undersuch a degree of tension as to prevent shrinkage of the thread, and

thereafter washing, treating with a dilute acid solution and againwashing. The treatment with the mercerizing solution may be continuedfor one to five minutes, more or less. If sodium sulphide solution isused as the shrinking agent, it

also will act to desulphurize the artificial threads. Theyals'o may berefined or decolorized by treating them with a warm .or hot solutioncontaining 10% of alkali sulphide (calculated as N8:S.9H2O) or with awarm or hot alkali hydrosulphide solution of equivalent strength. Thislatter treatment is claimed in a copending case, Patent No. 2,004,875.

It is impossible to indicate every condition for success in everyparticular case and it is to be understood that preliminary experimentcannot be avoided to find what are the best conditions, when using aparticular cellulose, a particular form of hydroxy-alkyl cellulosexanthate and particular details of the shaping and coagulating forexample, spinning operation.

accuser The following examples of operation serve as a practicalillustration of the present invention, which, however, is in no waylimited to the examples; the parts are by weight:

Example 1 Any one of the crude hydroxy-alkyl cellulose xanthatesobtained in Examples 1 or 4 or 6 or 7 (the latter two as far as theyrelate to 100 parts of a-monochlorohydrine or ethylene chlorohydrine) orExamples 9 or 12 or 15 or 17, of my concurrently filed application435,647, (now Patent 1,858,097) is dissolved in such a quantity of waterand caustitc soda as to yield a solution containing about 6.5 to 7 percent. of the parent hydroxy-alkyl cellulose and 8 per cent. of NaOH. (Incase of Example 17 in which the cellulose dihydroxy-propyl ether isxanthated in the dissolved state, the proportions of NaOH to water andcellulose desired in the spinning solution are arranged beforexanthating takes place.) The solution is now filtered three timesthrough cotton and after it has attained a total age of 96 to 100 hours(in the case of Examples 1 or 6 or 7 or 9 or 12) or of 48 hours (in thecase of Example 17). The solution is spun as follows:

(a) The spinning solution is pressed at a. speed of 3.3 ccm. per minutethrough a platinum nozzle (having 54 holes of 0.1 mm. diameter) into abath containing 65 to 73 per cent of H2804 and having a temperature of16 C. and the length of immersion of the threads in the sulphuric acidbeing about 20 cm.; then the threads are allowed to pass through the airfor 120 cm. and wound on a spool revolving at a speed which produces aspeed of spinning of about 18 111. per minute. In the air passage, 3glass rollers are arranged angularly to one another, over which rollersthe thread runs, thus applying an additional stretch or tension to thethreads. The lower part of the spool revolves in water, so that thesulphuric acid is removed or is considerably diluted as soon as thethread arrives at the spool. The threads are then washed, purified,twisted and finished in the usual manner. 4

The thread obtained in this manner consists of individual filaments ofabout 2 to 2.5 deniers each.

(b) The mode of operation is the same as in Example (a) but with thediiference that the spinning bath contains 55 to 60 per cent of H2304-(c) The mode of operation is the same as in (a) or (b), but with thevariation that the temperature of the spinning bath is 0 C.

(d) The same mode of operation as in (a) or (0). but with the differencethat only 1.6 ccm. of the spinning solution is discharged per minutethat the nozzles have 100 perforations of 0.08 mm. diameter, and thatthe spinning bath contains 61' to 70 per cent of H2804.

The titre of the individual threads is about 0.6 to 0.7 denier.

(e) The same mode of operation as in (d), but with the difference thatthe spinning bath contains 55 per cent of H2804.

(f) The same mode of operation as .in (a), or

(b), or (c), but with the difference that 3 ccm. of'

the spinning solution are discharged per minute and that the speed ofspinning is 30 m. per minute.

The titre of the single filament is about 0.6 to 0.9 denier.

(g) The same mode of operation as in (a) or (0), but with the differencethat 6.6 ccm. of the spinning solution is discharged per minute, that athe nozzles have 100 perforationsof 0.08 mm.

diameter, that the speed of spinning is m. per minute and that thesetting bath contains 64 5 per cent. of H1804.

The titre of the individual threads is about 1.2 to 1.4 denier.

(h) The same mode of operation as in (a), but with the difference thatthe spinning bath o contains 60 per cent. of H2804.

(i) The same mode of operation as in (d) but with the difference that 3ccm. of the spinning solution is discharged per minute, that the nozzleshave 24 perforations of 0.1 mm. diameter, 15 that the setting bathcontains 61 to 70 per cent. of H2804 and has a temperature of 0 C., andthat the length of immersion of the thread in the setting bath is 80 cm.

The titre ofthe individual threads is about 4.5 20 to. 5 denier.

(k) The same mode of operation as in (i) but with the difference thatthe spinning bath contains 55 per cent of H2804.

(l) The same mode of 'operation as in (g) or 25. (h) but with thedifierence that the spinning solution is discharged at a speed of 14ccm. per minute, that the speed of spinning is about 100 to 120 111. perminute, that the thread is not subjected to additional stretch, and thatthe length 3 1 of immersion is 80 to 100 cm.

The titre of the silk is about 0.9 to 1 denier per individual filament.

Example 2 35 Any one of the crude hydroxy-alkyl cellulose xanthatesobtained in Examples 2 or 10 or 11 of my Patent No. 1,858,097 isdissolved in such a quantity of water and caustic soda as to yield asolution containing about 6.5 to 7 per cent of parent hydroxy-alkylcellulose and 8 per cent. of NaOH. The solution is now filtered threetimes through cotton and after it has attained a total age of 96 to 100hours, the solution is spun as in the preceding example.

The concentrations of the setting baths are as follows:

In spinning method (a) and (c): 55 to 65 pe cent. of H2804.

m spinning method (b) per cent. of H2504.

Inspinning method (e): 50 per cent. of H2804.

In spinning method (f): 58 to 60 per cent. of H2504.

In spinning method (g): H2804.

In spinning method (1): to 64 per cent. of H:SO4.

per cent 1 55,

Example 3 Mode of procedure as in Example 1 or 2, but with thedifference that, instead of the hydroxyalkyl cellulose xanthatesolutions used therein, the hydroxy-ethyl cellulose xanthate solutionobtained according to Example 20 of my U. 8. pato5 ent 1,858,097, may beused. This solution contains about 6.5 to 7 per cent of thehydroxy-ethyl cellulose and about 8 per cent. of NaOH. The solution isnow filtered three times through cotton and after it has attained atotal age of 96 to hours it is spun as in the preceding example.

The concentrations of the setting baths are as follows:

In spinning method (a) and (c): 60 to 62 per cent of H2804. Y 75.

-In spinning method (1)) 55 per cent of H1804. In spinning method (d) 58to 61 per cent of In spinning method (e) 55 per cent oi. H2804.

"In spinning method (I): 58 to 61 per cent of In spinning method (9):

, In spinning method (I):

58 to 62 per cent of 50 to 55 per cent of Example 4 The solution of the1:2-dihydroxy-propyl cellulose xanthate obtained as described in Example18 or 19 of my U. S. Patent 1,858,097 or the solution of theh'ydroxy-ethyl cellulose xanthate obtained as described in Example 21 ofmy U. S. Patent 1,858,097 and in either case containing 6.5 to '7 percent of the respective hydrbxy-alkyl cellulose and 8 per cent of NaOH isnow filtered three times through cotton and after it has attained atotal age of 48 hours, spun as in the pre- In spinning method (I): 40 to46 per cent H2804.

Example 5 The process is conducted as in any one of the precedingexamples, but with the difierence that the. respective hydroxy-alkylcellulose xanthate is dissolved in such an amount of water and causticsoda that the solution contains 7 per cent of the parent hydroxy-alkylcellulose and 5 per cent of NaOH.

Example 6 The process is conducted as in any one of the precedingexamples but with the difference that a bath containing in each liter,160 grams of H2504 and 320 grams of Na2SO4 is used as the coagulating orsetting bath at about 45 C.

Example 7 The process is conducted as in any one of the precedingexamples, but with the'difi'erence that before entering the setting baththe thread-like stream is conducted through one of the following baths.

1) a solution of ammonium sulphate of 25 to 30 per cent strength, or n(2) a bath consisting of 500 parts of sodium bisulphate, 76 parts ofsulphuric acid of 66 B.

" and 587 parts of water, which bath may be kept at room temperature orat a raised temperature, for instance 50 (3., or

(3) a bath consisting of 982 parts of water, 180 parts of sodiumsulphate, 60 parts of ammonium sulphate, parts of zinc sulphate, 135parts of glucose, and 128 parts of sulphuric acid of 66 B.

, Example 8 The process is conducted as in any one of the precedingexamples, but with the diflerence that the hydroxy-alkyl cellulosexanthate is dissolved in so much water and caustic alkali as to yield asolution containing about 3 per cent of parent hydroxy-alkyl celluloseand 5 per cent of NaOH.

For the carrying out of this example it is recommended to start with acellulose of high viscosity (determined by the customary methods).

Example 9 The process is conducted as in any one of the precedingexamples, but with the exception that a sulphuric acid of 10 per centstrength is used as the spinning bath: the temperature'of this bathbeing 16 C. or 4 C.

Example 10 The process is conducted as in Examples 1 to 7, but with thediflference that the alkali cellulose is allowed to mature for 48 hoursat'15 to 20 C. 20

. Example 11 Mode of procedure as in any one of' the preceding examples,but with the difference that to the spinning solution 10 to 30 partsof'a-dichlorohydrine or a-monochlorohydrine or ethylene chlorohydrine to100 parts of the hydroxy-- alkyl cellulose xanthate contained therein,are added after the dissolving step.

In those of the foregoing examples, in which strong acids are used, theaction of the acid may be interrupted also by subjecting the threadsleaving the bath consisting of, or containing strong acids, to a lowtemperature, for instance -5 to 15 C. before it is washed, which, forinstance may be done by collecting it one. hollow spool containing acooling agent, for instance solid carbonic acid, or a freezing mixture,or ice. The manufacture of staple fibre will be entirely clear from theforegoing examples.

After the threads have been washed they may be heated or steamed at hightemperatures (for instance l00-ll0 C.) before or after the dryingprocess.

Bleaching of the threads may be conducted in the known manner.

The threads may be desulphurized for instance by treating them with ahot or warm solution of alkali metal sulphide, containing at least 5% ofalkali metal sulphide (calculated as NazSBHzO) for example by treatingthem with a solution of Na=S.9H:O of 10 per cent strength for 5 to 60minutes or with a solution of NazSBHzO of 30 per cent strength for about5 to 10 minutes at 100 C.

Example 12 A xanthate solution, produced in the manner described inanyone of the foregoing examples is introduced in the known manner into.one of the precipitating liquids mentioned in one of the foregoingexamples, through a suitable hopper or slit, and the coagulated filmband, after having been run through this bath, is washed in the knownmanner and dried.

Example 13 A cotton material is impregnated or filled or coated, one orseveral times in a suitable machine for instance a padding machine or aback filling machine, or a spreading machine, with a xanthate solutionproduced in the manner described in one of the foregoing examples towhich solution a filling material, such as talc or china clay or zincwhite for instance 100 to 200 per cent. calculated on the weight of thehydroxy-alkyl cellulose), or a dyestufl or a pigment, such as mica, orlampblack, may be added and without being dried, if necessary in a stateof tension, is passed through a bath having the composition of one ofthe coagulating baths mentioned in the foregoing examples. The dressedor coated fabric isthen washed and dried.

In determining whether or not the alkali cellu-.

' 7 Sodium hydroxy-cthyl mlluloee (Cosmos-10in) ONa Sodium 1:2dihydmxy-mpyl cellulose and artificialthreads in particular, takingaccount of the fact that this viscosity will also depend on the kind ofcellulose used as starting material. If it is desired to give thehydroxy- 'allnrl cellulose xanthate solution a definite viscoslty thenthe alkali cellulose produced from the kind of cellulose used as parentmaterial, is subjected to a maturing process, if without maturing thiskind of cellulose yields a higher viscosity than that desired. If,however, it exhibits from the first (that is without maturing) thedesired degree of viscosity, then maturing is unnecessary. Now asviscosities of the different kinds of cellulose on the market (lintersand woodpulp) differ very much from one another, the question ofmaturing depends in most cases on the one handon the viscosity desiredofthe solution intended for the manufacture of artiflcial material, andon the other hand on the viscosity of the kind of cellulose beingworked.

Without restricting the present invention to any lower or upper limitsof tenacities or extensibility, it may be mentioned by way of examplethat it is possible to produce, by the present process, artificialthreads, when using coagulating baths that exert no plasticizing action(or substantially no plasticizing action) on the freshly coagulatedmaterial, which products have a dry tenacity exceeding 2 grams and insome cases at least 2.5 and even 3 grams per denier or even more, andwhich, without being subjected to any special after-treatment, have anextensibility of at least 12 and in many cases 16 to 18 and even 20 to24 per cent. and, when plasticizing baths are used, a dry tenacity of atleast 2 grams per denier and even 3 to 4 grams per denier or more, andwhich have a good extensibility of about 7 to and in some cases even 10to Whether or not the coagulating bath has a plasticizing action, thewet tenacity of the thread is substantially over 1 gram per denier.

I have referred above to certain matter discussed in detail in myconcurrent application 435,647 new Patent No. 1,858,097, which caserelates to technically valuable cellulose compounds obtained by actingupon hydroxy-alkyl derivatives of cellulose or of its near conversionproducts with carbon bisulphide in presence of a basic substance,particularly caustic, alkali.

\ According to their mode of formation, chemical viour and resultsofanalysis, the said cellulose compounds, in their free state, arebelieved to be hydroxy-alkyl-cellulose xanthlc acids(dithiocarbomclhydroxy-alkyl cellulose esters) and in the form of theirsalts, hydroxy-alkyl cellulose xanthates (salts ofdithiocarbonic-hydroxy-alkyl cellulose esters).

The reaction leading to the formation of the said cellulose compoundsmay (I believe) be represented for the simplest types by the followingequations in which, as examples, are taken. the hydroxy-ethyl celluloseand the 1:2 dihydroxypropyl cellulose.

1:2 dlhydroxypropyl cellulose xanthate The present specification(435,648) refers to certain of the examples given in 435,647 (now PatentNo. 1,858,097) namely the following ones:- I

, Example 1 1000 parts of wood-pulp (moisture 9 to 10 per cent) or'l 0parts of cotton linters (moisture 7 to 8 per grit) are steeped in 20,000parts of caustic sod solution of 18 per cent strength at 15 C., and thereaction mixture is allowed to stand for 3 hours at room temperature.After this time the alkali cellulose is pressed down to 3400 parts andcomminuted in a shredder for 3 hours at 12 to 13 C., whereupon 100 partsof a-monochlorohydrine are added graduallyv (i. e. in a few portions),and the reaction mass kneaded in a shredder for about 3 hours at C.Thereafter the reaction mass is transferred to a vessel provided with alid, and kept in the closed vessel for 21 hours at 20 C.

A sample taken at the time shows that the mass in part has becomesoluble in dilute caustic soda solution (for instance of 10 per centstrength) and that the filtered solution of the material in NaOHsolution, on being acidified with dilute sulphuric acid, yields a bulkyprecipitate.

The reaction mass is now placed in a filter press or on a strainingcloth and-washed with water until free from alkali, whereupon it ispressed down to about three to four times the weight of the parentcellulose. The water content of the pressed product is determined bydrying a sample at 105 Ci The mass is now (at 15 C.) well mixed withsuch an amount of water and caustic soda as, together with the waterpresent in the mass, will give 20,000 parts of a caustic soda solutionof 18 per cent strength.

The reaction mixture is now allowed to remain at room temperature for 3hours, whereupon it is pressed down to 3400 parts to 4000 parts andcomminuted in a shredder for 3 hours at 12 to 13 C. Immediately aftershredding 600 parts of carbon bisulphide are added, and the reactionmass placed in a closed vessel and kept therein for 10 hours at 19 C.The excess carbon bisulphide is blown off during 15 minutes, and thexanthated mass is disolved in water and caustic soda, for example so asto yield a solutioncontaining about 5 to '7 per cent '01 the dry residueof the washed and pressed hydroxy-alkylated product and 8 per centofcaustic soda. 4

' The solution is practically tree from undis solved particles andprecipitable with strong solutions of salts, for example ammoniumchloride or sodium chloride or ammonium sulphate or alcohol, or acids,for instance sulphuric acid or hydrochloric acid, or acid salts, forinstance sodium bisulphate.

- It is found that the precipitate obtained by addition of ethylormethyl alcohol under stirring, is collected on a filter, washed a fewtimes with alcohol, extracted with ether and dried at room temperatureunder reduced pressure, is an almost colorless, flocculent or lumpysubstance which is readily soluble in caustic alkali solution. Itssolutions are precipitated on being acidified, for example withsulphuric acid. On being analyzed according to Zeisels method(decomposed in strong hydriodic acid) the substance obtained from thesolution by precipitating it with alcohol as well as the washed anddried substance precipitated from the solution by means of sulphuricacid yields 1.79 per cent of CaH-zO.

' If both substances are boiled under reflux with an alcoholic causticpotash solution of 20 per cent strength or with an aqueous causticpotash solution of 20 per cent for 24 hours, all

four products are thoroughly washed until free from alkali, extractedwith alcohol and ether, dried and the amount of 031110 determinedtherein.

Analyses (of particular samples) give the following C3H'zO-figures:

(1) Substance precipitated with alcohol boiled with alcoholic 1.93 percent.

(2) Substance precipitated with alcohol and and caustic potash solution:

boiled with aqueous caustic potash solution: 1.89

per cent.

(3) Substance precipitated with sulphuric acid and boiled with alcoholiccaustic potash solution: 1.78 per cent.

(4) Substance precipitated with sulphuric acid and boiled with aqueouscaustic potash solution: 1.91 per cent. This propoxyl figure 1.78,mentioned above, corresponds to one dihydroxypropyl group to about17CsHmO5-m0lecular units of cellulose.

Example 2 The process is conducted as in Example 1, with the differencethat, instead of 100 parts, 200 parts of a-monochlorohydrine areemployed.

The working up of the xanthate is carried out as in Example 1.

The properties of the final product and of its solutions are similar tothose of the final product obtained in Example 1.

. Example! v The processis conducted as in Example 1, but withthejdifi'erence that, instead of the 100 parts of a-m'onochlorohydrine,100 parts of ethylene chlorohydrine are added to the alkali cellulose.The .working up otthe xanthate is carried out as inlExample 1. v Theproperties of the final product and of its solutions'are similarto thoseof the final product obtainedin Example 1.

--Ea:ample 6 The process is conducted'as in one 01 the precedingexamples, with the exception that, im-

mediately after havingbeen mixed with the 15 va-monochlorohydrine orethylene chlorohydrine respectively for 3 hours, the reaction mass iswashed and then dealt with as in any of the preceding examples.

The properties of the final product are similar 9 to those obtained inthe preceding examples.

' Example 7 Mode of procedure as in any of the preceding examples, withthe difference that the reaction Example. 8

1000 parts of wood-pulp (moisture 9 to 10 per cent) or 1000 parts ofcotton'linters (moisture '7 to 8 per cent) are steeped in 20,000 partsof caustic soda solution of 18 per cent strength at 40 15 C., and thereaction mixture is allowed to stand for 3 hours at room temperature.After this time the alkali cellulose ispressed down to 3400 parts andcomminuted in a shredder for 3 hours at l2"to 13 C., whereupon 100 partsof a-IIIOXIOChlOl'OhYdIil'lG are added gradually (e. g. in a"fewportions) and the reaction mass kneaded in a shredder for about 3 hoursat 20 C. Thereafter the reaction mass is transferred to a vessel,provided with a lid, and kept in the closed vessel for 21 hours at 20 C.

Immediately thereafter 600 parts of carbon bisulphide are added andallowed to act for 8 hours at 19 to 20 C. The excess carbon bisulphideis now blown off during 15 to 20 minutes, and the thus produced xanthatedissolved, for example in such a quantity of caustic soda and water thatthe solution contains the equivalent of about 5'to 6 per cent. of parentcellulose and 8 I per cent of NaOH.

The solution is practically free from undissolved particles andprecipitable with strong solutionsof salts, for example ammoniumchloride or sodium. chloride or ammonium sulphate, or alcohol, or acids,for instance sulphuric acid or hydrochloric acid, or acid salts, forinstance sodium bisulphate.

Then the precipitate obtained by addition of ethylor methyl alcoholunder stirring is collected on a filter, washed a few times withalcohol, extracted with ether and dried at room temperature underreduced pressure. The product is-an almost colorless, fiocculent orlumpy substance, which is readily soluble in caustic alkali solution andwater. Both solutions are precipitated on being acidified, for examplewith sulphuric acid.

The analytical results are similar to those obtained in Example 1.

Example 9 Example 10 The process is conducted as in Example 8, but

with the diilerence that instead of 100 parts of' a-monochlorhydrine 200parts of ethylene chlorhydrine are employed.

- The working up of the xanthate is carried out as in the precedingexamples.

The properties of the final product obtained are similar to those of theproduct obtained in Ex ample 1.

Example 11 The process is conducted as in Example 8, but with thedifference that, instead of 100 parts of a-monochlorhydrine, 300 parts01' ethylene chlorhydrine are employed.

The working up of the xanthate is carried out as in one of the precedingexamples.

The properties of the final product and of its solutions are similar tothose of the final product I obtained in Example 1.

Example 12 The process is conducted as is Example 9, but

Example 15 1000 parts of wood-pulp (moisture 9 to 10 per cent) or 1000parts of cotton linters (moisture TI to 8 per cent) are steeped in20.000 parts 01' canstic soda solution of 18 per cent strength at 15 C.,and the reaction mixture is allowed to stand for 3 hours at roomtemperature. After this time the alkali cellulose is pressed down to3400 parts and comminuted in a shredder for 3 hours at 12 to 13 C. Thecomminuted mass is thereafter left in the shredder and its temperatureraised to 20 C., whereupon 300 parts of ethylene chlorohydrine andimmediately afterwards 600 parts of carbon bisulphide are added'theshredder well closed and the kneading continued for 5 hours at about 20C. The excess carbon bisul-' phide is blown off during 15 'to 20minutes, and the xanthate is dissolved in caustic soda and water in suchproportions that the solution contains the equivalent of 3 per cent. ofthe parent.

' cellulose and 8 per cent of NaOH.

The working up 0! the xanthate is carried out- Example 17 '1000 parts ofwood-pulp or cotton lintcrs are solutions are similar to those of thefinal product steeped in 20.000 parts of caustic soda solution of 18 percent strength at 15 0., and the reaction mixture is allowed to stand for3 hours at room temperature. After this time the alkali cellulose ispressed down to 3,400 parts and comminuted 5 in a shredder for 3 hoursat 12 to 13 C., whereupon 200 parts of a-monochlorhydrine are added in afew portions, and the reaction mass kneaded in a shredder for 3 hours at20 C. Thereafter the reaction mass is transferred to a m vessel,provided with a lid and kept in the closed vessel for 2| hours at 20 C.

A sample taken at that time shows that the mass in greater part hasbecome soluble in dilute caustic soda solution (for instance of 10 percent 15 strength), and that the filtered solution, on being acidifiedwith dilute sulphuric acid, yields a bullw precipitate.

The mass is now dissolved in 75,000 parts of a caustic soda solution of8 per cent strength, 20. wherein it dissolves not completely, but with aresidue. After standing for 12 hours at'room temperature, the suspensionis filtered and the clear filtrate precipitated by acidifying withsulphuric acid of 15 per cent strength. The fioccu- 2t lent precipitateis freed from the. mother liquor in a filterpress or on a strainingcloth, washed with water until free from acid, pressed and afteritswater content has been determined dissolved in such an amount ofcaustic soda and water as to yield a solution containing 7 per cent ofthe cellulose 1:2 dihydroxy-propyl ether and 8 per cent of NaOH. To thissolution parts of carbon bisulphide (calculated on the weight of thecellulose 1:2 dihydroxy-propyl ether) are added, 35 and the reactionmixture kept shaken for 20 hours at 20 C.

The properties of the final product and of its obtained in Example 1. 40

The CaHvO-figures (on particular samples) are as follows:

(1) Body precipitated with sulphuric acid: 2.53%.

(2) Body P ecipitated with sulphuric acid and 45- boiled with. alcoholiccaustic potash solution: 2.05%.

- Example 18 Example 19 Mode of procedure as in Examples 1'7 or 18, butwith the exception that, instead of 200 parts, 300 parts ofu-monochlorohydrine are used.

The working up of the xanthate is carried out 65 as in Example 17.

The properties of the final product and of its solution are similar tothose of the final product obtained in Example 17.

Example 20 The process is conducted as in Example 18, but with thediflference that, instead of the 200 parts of a-monochlorohydrlne, 200parts of ethylene chlorohydrine are used. 75

Example 21 I The process is conducted as in Example 17, but with thedifierence that, instead of the 200 parts of a-monochlorohydrine, 300parts of ethylene chlorohydrine are employed.

In the specification and claims, wherever the context permits, "theexpression "cellulose includes the near conversion products and oxida--tion products of cellulose such as cellulose hydrate, hydroceliuiose andoxycellulose.

The expression hydroxy-alkyl derivative of cellulose" or bydroxy-alkylether of cellulose" or hydroxy-alkyl cellulose" used in thespecification and claims includes thosederivatives of cellulose in whichat least one hydroxylhydrogen atom of cellulose, of a cellulose hydrate,of a hydrocellulose, or of an oxycellulose is replaced a monohalohydrinein the-presence of an alkali.

The expression "halohydrine" used in the specification andthe claims,includes (wherever the context permits) the compounds containing both ahalogen and a hydr'oxyll group which may be regarded as being derivedfrom poiyhydrorw alcohol by the partial exchange of the hydroxyl groupsand chlorine, bromine or iodine (or from a monoor polyhydroxy alcohol bythe substi .tution of one or more hydrogen atoms in the alcohol(radical) and the derivatives (such as the V esters) or internalanhydrides (such as epi-' chiorohydrine) of such halohydrines, orsubstances or mixtures of substances which are capable of yielding suchhalohydrines.

The expression strong mineral acids denotes sulphuric acid of at least35 per cent oi H2804, preferably at least 45 per cent. of H2804, and asregards the other mineral acids, solutions of equivalent strength.

Instead of sulphuric acid of at least 35% strength or stronger, nitricacid of 60 to 90% strength, or phosphoric acid of 67.5 to 99% strength,or arsenic acid of 60 to 90% strength, or a solution containing 60% ofZnClz and 5 to 6% of HCl, or a strong solution of zinc chloride withoutaddition of'HCl, can be used, as plasticizing agents, the use of suchbaths being included in the appended claims, in the expressionplasticizing liquids. I

The expression strong sulphuric acid" or sulphuric acid containing atleast about 35 per per cent. of sulphuric 'acid monohydrate denotessulphuric acid having a content of 35 to 98 per cent. of H2804.

The term hydroxyalkyl is intended to include the halogenated ornon-halogenated radicals of dior polyhydric alcohols in conjunction withone or more oxygens or hydroxyls.

The expression shaped artificial structures" used in the specificationand claims is intended to include: --artiflcial-threads, particularlyartificial silk and staple fibre, film, shaped plastic masses, appliedfinishes and, coatings of every kind, flnishings, fillings, anddressings on textile fabrics, sizings on yarn, paper-like surfacing,applied paper sizings, artificial leather, transparent paper or cloth,book cloth and tracing-cloth and the like.

droxyalkyl cellulose xanthate into the shape of the desired artificialstructure, and acting upon the shaped solution with a coagulating agent.

2. A process of making artificial structures which comprises bringing asolution of a hydroxy-alkyl cellulosexanthate, which hydroxyalkvlcellulose is made by treating cellulose with a hydroxy-alkylating agentin the presence of alkali, into the shape of the desired artificialstructure, and acting upon the shaped solution with a coagulating agent.

3. A process '0! making artificial structures which comprises bringing asolution of a hydroxy-alkyl cellulose xanthate, which hydroxyalkylcellulose has been made by treating cellul lose with a halohydrine inthe presence of alkali, into the shape of the desired artificialstructure, and acting upon the shaped solution with a coagulating agent.

4. A process as in claim 1, in which a shaped stream of a hydroxy-alkvlcellulose xanthate solution is caused to enter through at least onesuitably shaped opening into a coagulating bath.

a 5. A process as covered in claim 1, wherein any coagulating bath knownin the viscose industry is used as the coagulating agent.

6. A process as in claim 1, in which the solution of the xanthate of thehydroxy-alkyl derivative of cellulose also contains cellulose xanthate.

7. A process as covered in claim 1, wherein the t0 hydroxy-alkylcellulose xanthate is a xanthate of a hydroxy-alkyl derivative ofcellulose which hydroxy-alkyl cellulose is itself at least partiallysoluble in caustic alkali solution.

8. A process as in claim 1, in which the artificial structure is treatedwith a shrinking agent.

9. A process as covered in claim 1, wherein the xanthate of ahydroxy-alkyl derivative of cellulose is a xanthate of amonohydroxy-alkyl derivative, and is made by reacting upon a cellulosic40 material with a hydroxy alkylating reagent in the presence of analkali.

10. A process of making a shaped artificial structure, which comprisesgiving to a solution containing a xanthate of a hydroxyalk'yl ether ofcellulose, prepared by acting upon cellulose with a hydroxy-alkylatingagent in presence of caustic alkali, the shape of an artificialstructure by extruding said solution through a shaped opening directlyinto a coagulating bath, and

continuously drawing the coagulated artificial staructure away from saidshaped opening.

11. A process as covered in claim 10, wherein during a part ofitsjourney from the shaped opening to a collecting device,- the artificialstructure is given a stretching additional to such as is necessary forthe formation of the artificial structure.

12. A process as covered in claim 10, in which the shaped opening is ofsuch a construction as to deliver a thread-like stream of the solution.

13. A process as covered in claim 10, in which the shaped opening is ofsuch a construction as to deliver a thread-likestream of the solutionand in which the thread is under tension during a portion of its journeyfrom said opening to the collecting device.

14. A process as covered in claim 10, wherein additional stretch isapplied to the artificial structure while in the bath. v

15. A process as covered in claim 10, wherein additional stretch isapplied to the artificial structure while between the bath and thecollecting device. 75

18... A processas coveredinclaim 17, whereina solution of a-hydroxyalkylucellulose xanthate,

having the .formof'therdesired artificial structure is acted uponwith-an agent which has a coagulating'efiecton the shaped solution andwhich also has a plasticizing effect on the freshlycoagulatedartificialstructure,

, 19. A process as covered in claim 1'7, wherein the coagulating andplasticizing are conducted in a bath of a. medium. containing at leastper cent. of sulphuric. acid rhqnohydrate.

. 20. A process as in claim 17, in which the coagulating and "plasticizpg actions are effected in a bath containing mineral acid equivalent instrength to sulphuric acid of at least 35% H2804. 21; A processwhichccmprises treating a solution containing a 'xanthate of ahydroxy-alkyl derivative=of"cellulose,having the form of an artificialstructure; with-a coagulating agent and thereafter with a plasticizingagent.

22. A process which comprises treating a solution' emai'ning'a-xan'thate of a hydroxy-alkyl derivative of cellulose, having the formof an artificial structure, with a coagulating agent and thereafter witha bath containing a mineral acid equivalent to sulphuric acid of atleast 35% strength.

23. A process which comprises making a hydroxy-alkyl derivative ofcellulose by reacting upon cellulose with a hydroxy-alkylating agent inthe presence of an alkali, xanthating said hydroxy-alkyl derivative ofcellulose, and treating the xanthate in solution while having the formof the desired artificial structure, with a coagulating agent, axanthate of a hydroxy-alkyl derivative of cellulose, having the form ofan artificial structure, with a coagulating agent and thereafter with abath containing at least 35% 0f H2SO4.

24. Process as in claim 17, in which the xanthate solution containscaustic alkali.

25. A process as covered inclaim 10, wherein a softening agent is addedto the solution of the hydroxy-alkyl cellulose xanthate before itsconversion into the artificial structure.

26. A process as referred to in claim 17, wherein the action of theplasticizing agent is checked at a time not considerably after thearrival of the artificial structure at a collecting device.

27. A process of making an artificial structure which comprises forminga solution of a muthate of a hydroxy-alkyl derivative of cellulose, intothe form of an artificial structure, and thereafter plasticizing suchartificial structure during the completion of its manufacture, bytreating same with a mineral acid of a strength equivalent to sulphuricacid of at least 35%.

28. A process of making an artificial structure which comprises forminga solution of a xanthate of a hydroxy-alky'l derivative of cellulose,into the form of an artificial structure, and thereafter plasticizingsuch artificial structure during the completion of its manufacture, bytreating same with a mineral-acid of .a strength equivalent to sulphuricacid of at least 35% and checking the action of -said.mineral;.acid,when the plastic has been sufliciently accomplished.

1129. A; process as inclaim, 28, in checkingtis. eflected byrefrigerating the artificial structure.-. a 1

. -30. .A-process as in .claim 28., in which the checkingdseifected bywashing. ."31. A-proeess as inclaim 1-, in which a-.halo.- hydrine isadded .to the solution of the hydroxy.- alkyi .-cellu-lose xanthatesolution to thereby improve the final product. i

- 32. A process. as covered in claim 1, wherein the hydroxy-alkylcellulose xanthate solution to be worked-up into an artificial structureis produced by treating an alkaline solution containing a hydroxy-alkylderivative of cellulose, which is at least partially soluble in causticalkali solution but insoluble in water, with carbon disulphide.

33. A process as covered in claim 1, wherein the-solution to be workedup into an artificial material is produced by a method which includesexposing a reaction product resulting from the treatment of alkalicellulosewith a halohydrine, to the action of carbon bisulphide in thepresence of sufiicient caustic alkali for efi'ecting the xanthatingreaction.

34. A process which comprises introducing a solution containing axanthate of a hydroxyalkyl derivative of cellulose through a shapedopening of such a shape as to form an artificial structure, into asetting bath, plasticizing the artificial structure by action thereonwith a bath having a plasticizing action at least equal to that ofsulphuric acid of 35% concentration, and leading said artificialstructure to a collecting device.

which the 35. A process as covered in claim 34 in which 40 the shapedsolution is delivered into a setting bath of which the acidity (figuredas sulphuric acid) is below 35%, to coagulate the artificial structure,and in which process the coaguiated artificial structure then passes toanother bath of mineral acid of a strength equivalent to at least 35%H2804 to plasticize said artificial structure.

36. Process as covered in claim 34, in which the setting bath is asolution containing a mineral acid of a strength equivalent to sulphuricacid of at least 35%, to coagulate and plasticize the artificialstructure in said bath.

37. A process as covered in claim 1, wherein the solution to be workedup into an artificial structure, is produced by exposing the crude reaction mass resulting from the treatment of alkali cellulose with ahalohydrine, to the action of carbon bisulphide, and thereafterdissolving the thus obtained reaction mass.

38. A process as covered in claim 1, wherein the solution to be workedup into an artificial structure, isv produced by reacting upon cellulosewith a halohydrine, and treating the hydroxyalkyl derivative ofcellulose thereby produced, while in the presence of a caustic alkali,with carbon bisulphide and thereafter dissolving the thus obtainedreaction mass.

39. The herein described process of producing artificial structures ofhigh tensile strength and of at least fairly good extensibility whichcomprises introducing a shaped stream of a solution of a xanthate of anetherified derivative of cellulose intoa coagulating bath andplasticizing the freshly coagulated artificial structure, all withoutsubjecting the formed artificial structure to additional stretch, aftercontacting the same with the plasticizing agent.

40. The herein described process of producing artificial structures ofhigh tensile strength and of at least fairly good extensibility whichcomprises introducing a shaped stream of a solution of a xanthate of ahydroxy-alkyl ether of cellulose formed by reaction of a halogenhydrinupon a cellulosic body in the presence of an alkali, into a coagulatingbath, all without subjecting the formed artificial structure toadditional stretch, after contacting the same with the coagulating bath.

41. As new products, shaped artificial structures containing ahydroxy-alkyl derivative of cellulose, and which products have atenacity, in the dry state, equivalent to over 2 grams per denier andwhich products have an extensibility of at least 7%, which products areproduced by shaping a solution of a xanthate of a hydroxyalkylderivative of cellulose into the appropriate shape, and coagulating theso shaped material.

42. Artificial thread or filaments containing a hydroxy-alkyl derivativeof cellulose, such product having a dry tenacity of over 2 grams perdenier, and an extensibility of over 7%, which products are produced byshaping a solution of a xanthate of a hydroxy-allryl derivative ofcellulose into the appropriate shape, and coagulating the so shapedmaterial.

43. As a new product, an artificial thread which consists essentially ofat least one hydroxycellulose and which products have a dry tenacity 10equal to that of a thread having a dry tenacity not less than 2 gramsper denier, which products are produced by shaping a solution of axanthate of a hydroxy-alkyl derivative of cellulose into the appropriateshape, and coagulating the so shaped 15 material.

45. As a new product, artificial thread containing a hydroxy-alkylderivative of cellulose, which thread has a dry tenacity exceeding 2grams per denier, and a wet tenacity exceeding 1 gram per 20 denier, andan extensibility exceeding 7%.

46. A process as claimed in claim 1, in which a precipitate obtained byacidifying the solution of the hydroxy-alkyl cellulose xanthate, withsulphuric acid, after said precipitate is washed 0 and dried, upon beingdecomposed by strong hydriodic acid according to Zeisel's method, yieldsalkyl iodide in an amount which is stoichiometrically equivalent toabout 1.78% to 2.81% 30 oi propoxyl.

LEON IJLIENFEID.

